Evaporator Coil Temp. Protection; Auto-Mode - Heat Controller B-DVH09SD-0 Service Manual

DVC/DVH Inverter Mini-Split
However, no matter what value T4 is, if the unit
runs with T3<38°F(3°C) for more than 120
minutes and T3 remains lower than 29°F(-2°C)
for more than 3 minutes, the unit will enter
defrosting mode whether or not T2 drops more
than 41°F(5°C) or not.
9.4.2 Ending Defrosting Operation:
If any one of the following items is satisfied, the
defrost operation will end and the unit will return
to normal heating mode.
• T3 rises to be higher than TCDE1.
• T3 remains higher than TCDE2 for 80
seconds.
• The unit has run in defrosting mode for
10 minutes.
Indoor units
B-DVC/DVH 09, 12
B-DVC/DVH 18, 24
9.4.3 Defrosting Process：
DVC/DVH 9K,12K:
on
Compressor
off
on
4-way valve
off
on
Outdoor fan
off
on
Indoor fan
off
Indoor fan breeze(10s)
Where xx= 60seconds.
TCDE1 TCDE2
54°F(12°C)
47°F(8°C)
59°F(15°C)
Frequency F2 FrequencyF8
10s
xx
10s
no longer than 10m
DVC/DVH 18K, 24K:
on
Compressor
off
on
4-way valve
off
on
Outdoor fan
off
on
Indoor fan
off
Indoor fan breeze(10s)
Where xx=60seconds for 18K model
Where xx=90seconds for 24K model

9.5 Evaporator Coil Temp. Protection

When T2>140°F(60°C), the compressor will
turn off, but will restart when T2<119°F(48°C).
When T2>128°F(53°C), the compressor
frequency will decrease to a lower level and
runs at this level for 20seconds to protect the
unit. When the frequency decreases to
Fmax= F2 and T2>128°F(53°C) for 3 minutes,
the compressor will turn off. However, when the
coil temperature lowers to T2<119°F(48°C) or
T2 remains at 119°F(48°C) for 6 minutes, the
frequency will not be limited by the evaporator
coil temperature (T2).

9.6 Auto-Mode

This mode can be selected using the remote
control. The set temperature (Ts) can be
changed between 63-86°F (17-30°C).
30s
In auto mode, the machine will choose the
mode according to ΔT, where ΔT =T1-Ts:
ΔT=T1-Ts
ΔT>1°
-1°<ΔT≤1°
ΔT≤-1°
22
24
Heat Controller
Frequency F2 Frequency F8
10s
xx
10s
no longer than 10m 30s
Auto Mode Function:
Cooling
Fan-only
Heating